A subtractive method for decomposing muscle tension into individual twitches

Bates, Jason H. T.; Janssens, Shanice E. W.; Jiang, Tao; Hunter, I.

doi:10.1016/0010-4809(88)90013-4

Cited by 3 publications

(2 citation statements)

References 3 publications

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“…An extension to the model of muscle force which includes more detail and additional observations can be implemented by including twitch potentiation state as a more complex model parameter. For example, a framework for decomposition of tetanic forces into a series of individual twitches of different sizes was proposed by [42].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of linear and non-linear activation dynamics models for insect muscle

et al. 2019

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In computational modelling of sensory-motor control, the dynamics of muscle contraction is an important determinant of movement timing and joint stiffness. This is particularly so in animals with many slow muscles, as is the case in insects—many of which are important models for sensory-motor control. A muscle model is generally used to transform motoneuronal input into muscle force. Although standard models exist for vertebrate muscle innervated by many motoneurons, there is no agreement on a parametric model for single motoneuron stimulation of invertebrate muscle. Although several different models have been proposed, they have never been evaluated using a common experimental data set. We evaluate five models for isometric force production of a well-studied model system: the locust hind leg tibial extensor muscle. The response of this muscle to motoneuron spikes is best modelled as a non-linear low-pass system. Linear first-order models can approximate isometric force time courses well at high spike rates, but they cannot account for appropriate force time courses at low spike rates. A linear third-order model performs better, but only non-linear models can account for frequency-dependent change of decay time and force potentiation at intermediate stimulus frequencies. Some of the differences among published models are due to differences among experimental data sets. We developed a comprehensive toolbox for modelling muscle activation dynamics, and optimised model parameters using one data set. The “Hatze-Zakotnik model” that emphasizes an accurate single-twitch time course and uses frequency-dependent modulation of the twitch for force potentiation performs best for the slow motoneuron. Frequency-dependent modulation of a single twitch works less well for the fast motoneuron. The non-linear “Wilson” model that optimises parameters to all data set parts simultaneously performs better here. Our open-access toolbox provides powerful tools for researchers to fit appropriate models to a range of insect muscles.

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Section: Discussionmentioning

confidence: 99%

Evaluation of linear and non-linear activation dynamics models for insect muscle

et al. 2019

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“…Although the cause of such efficiency of HI-IT is unknown, several factors may be proposed. It is expected that a higher effort intensity should recruit more fibers (30), especially of the fast twitch kind (31), increased recruitment of stabilizing muscles and increased work of the heart and respiratory muscles (32), hence resulting in higher energy consumption rates compared to submaximal-intensity exercise. It is not surprising, therefore, that high-intensity intermittent exercise has been considered a good option for weight reduction both in rodent models (33) and in human obesity (34).…”

Section: Discussionmentioning

confidence: 99%

Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

Carnevali

Eder

Lira

et al. 2012

Braz J Med Biol Res

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We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min−1·mg protein−1) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a “time-efficient” strategy inducing metabolic adaptation.

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Contraction characteristics of the human quadriceps muscle during percutaneous electrical stimulation

Bergström

Hultman

1990

Pflugers Arch.

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Percutaneous electrical stimulation was used to study the force response of the quadriceps muscle. The normal frequency dependence of force was investigated in muscles at rest and after fatiguing contractions. A comparison between force response during fatigue induced by electrical stimulation at different frequencies and by voluntary work suggested equal changes in contractility, irrespective of the fatigue-inducing procedure. In fresh muscle we found a linear relation between stimulation period (10-100 ms) and force. At fatigue the relation changes with maximal deviation from linearity at a 50-ms period (20 Hz). There is a rapid recovery of high frequency force whereas the low frequency response remains low even after 30 min rest. At very low frequencies there is initially unexpectedly high force in fatigued muscle. This could be a result of increased fusion of twitches with initially prolonged relaxation time. To study the twitch summation we compared experimental results in a wide frequency range with computer-simulated twitch summations and present the frequency dependence of summation processes in human quadriceps muscle.

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A subtractive method for decomposing muscle tension into individual twitches

Cited by 3 publications

References 3 publications

Evaluation of linear and non-linear activation dynamics models for insect muscle

Evaluation of linear and non-linear activation dynamics models for insect muscle

Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

Contraction characteristics of the human quadriceps muscle during percutaneous electrical stimulation

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